Nickel-silicon-boron alloys



United,- States Patent NICKEL-SILICON-BORON ALLOYS Arthur T. Cape, Los Angeles, Calif., assiguor to Coast Metals, Inc., Little Ferry, N. J., a corporation of Delaware No Drawing. Application January 25, 1955,

Serial No. 484,081 1 1 Claim. (Cl. 75-171) This invention relates, asindicated, to nickel-siliconboron alloys.

In my. copending application, Serial No. 285,801, now Patent No. 2,743,177 there is disclosed a series of alloys containing nickel, silicon and boron, having unusual adherence properties, particularly'the ability to adhere to stainless steel and to pure molybdenum.

The alloys, as thus disclosed, contain silicon, in.

amounts of from about 2.5% to about 5.5%, and boron in amounts of from about 0.75% to about 5.25%, with the balance or remainder substantially all nickel, it being understood, however, that wherever the expression remainder substantially all nickel was used in the specification and claims of said application, the expression was to be construed as including, whenever present in the alloy, small amounts of. iron, manganese and chromium, in a total amount of less than I have discovered, as the result of further research in connection with alloys of this type, that the properties of the aforesaid alloys in certain directions can be markedly improved by incorporating in the alloy, chromium and iron in definite combined amounts greater than used in the alloy of said copending application.

The use of both chromium and iron in the improved alloy is mandatoryv instead of optional, the chromium being present in amounts of from 2% to about 9.5%, and the iron being present in amounts of from 1% to about 5%, the sum of the two being not less than 5% nor greater than 12%. In general, the ratio of the chromium to iron in the alloy should be approximately 7:3, the iron always being less than the chromium.

'By thus incorporating'chromium and iron in the alloys, 1 find that in addition to the other advantageous properties obtained in the alloys, as described in said copending application, the following advantages are obtained:

(a) The tendency of the boron and silicon to become oxidized, in an oxidizing atmosphere, is greatly lessened.

(b) By thus retaining the boron and silicon in the alloy, the properties of the alloy are more accurately maintained.

(c) Whilethe Rockwell hardnesses are of the same order of magnitude as the alloys of said copending application, the inherent hardnesses, i. e., the microconstituent hardnesses, are considerably increased, due to the presence of the chromium and iron in the ranges stated. The Knoop values of the three microconstituents are as follows:

( 3 Matrix material mium, has a matrix hardness of 769-980 and the hardness of the other constituent (dendrites) is 447-667.

The disclosure in said copending application is incorporated, by reference, in the present application. In this application, however, the expression the balance being substantially all nickel, as used in the claims, is to be construed as precluding anything other than traces of impurities, such as manganese or phosphorus.

It is to be understod that various changes may be made in the proportions of the ingredients of the alloy, without departing from the spirit of the invention or the scope of the appended claim.

This application is a continuation-in-part of my copending application, Serial No. 370,879 now abandonetl.

Having thus described my invention, I claim:

An alloy which is especially adapted for hard facing at relatively low temperatures, said alloy containing silicon in amounts of from about 2.5% to about 5.5%,

boron in an amount of from about 0.75% to about 5.25%. and chromium and iron in significant amounts adapted to greatly lessen the tendency of the boron and silicon to become oxidized, in an oxidizing atmosphere, and to increase considerably the micro-constituent hardnesses of the alloy, the chromium being present in an amount of from about 2% to about 9.5%, and the iron in an amount of from about 1% to about 5%, the sum of the chromium and iron being not less than 5% and not more than 12%, the iron beingalways less than the chromium, the balance of the alloy being nickel.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Mathewson: Modern Uses of Non-Ferrous New York: AIME, 1935, pages 81' and 82.

Nickel and Nickel Alloys, New York: International Nickel Co., Inc., 1941, section D, page 7.

Corbett et al.: Effects of Boron in Steel, Bureau of Mines Report of Investigations 3816, June, 1945, page 12.

Woldman et 11].: Engineering Alloys, 2nd edition, 1945, page 448. Published by the American Society for Metals,"

Metals. Compositions explained in 3d edition of same,

1954, pages 489, 490.

Metal Progress, August 1950, page 183. The Iron Age, vol. 175, No. 8, Feb. 24, 1955, page 79.

931-1080 v in comparison, the same alloy, but devoid of,chro-' 

